Thermostabilized chlorine-containing polymers

ABSTRACT

Compositions comprising an ester of aminocrotonic acid and 0.1 to 10 weight per cent of an organometal compound corresponding to the formula

Unite States Patent 1191 Weisfeld et al. [4 1 Apr. 3, 1973 s41THERMOSTABILIZED CHLORINE- 3,167,527 1/1965 Hechenbleikner ..260/45.75CONTAINING POLYMERS 7 3,412,139 11/1968 Eggensperger et a1......260/45.85

4 [75] Inventors: Lewis B. Weisfeld, Highland Park, 5/1966 Gaspam 260/4585 N.J.; Holger Andreas, Bensheim- Auerbach; Horst Miiller, Fuerth, Z ilgamlrier 2 i k both of Germany sszstant xqrrrmero e Attorney-Christen &Sabol [73] Assignee: Ciba-Geigg Marienberg Gmbl-l 22 Filed: Sept. 4,1970 [57] ABSTRACT [21] Appl. No; 69,988 Compositions comprising anester of aminocrotonic acid and 0.1 to weight per cent of an organometalcompound corresponding to the formula Foreign Application Priority DataSept. 12,1969 Germany ..P 19 46 235.2 MCZSM] wherein R, R and R" arealkyl radicals having 1 to 8 [52] U.S. Cl......260/45.75 K, 252/401260/45.75 R, carbon atoms and phenyl, Z is one-half oxygen or one-260/45.85 A, 260/899 half sulfur, a and b are 0 or 1, Me is tin or leadand n [51] Int. Cl. ..C08f /58 is an integer of 1 to 1000, preferably 1to 100, are use- 8] Field 01 Search 4575 ful heat stabilizers forhalogen containing resins. 45-35 252/401 Halogen containing resinssuitable for stabilization with these compositions are polyvinylchloride, References Cited polyvinylidene chloride, copolymers of vinylchloride UNITED STATES PATENTS with vmylldene chlor de, vinyl acetateand styrene as well as chlorinated mixtures of polyvinyl chloride and2,746,946 5/1956 Weinberg et al. ..260/45.75 polyolefins.

3,021,302 2/1962 Frey et al. 260/45 75 2,267,777 12/1941 Yngve 260/45 757 Claims, N0 Drawings THERMOSTABILIZED CHLORINE-CONTAINING POLYMERS -andpolyolefins must be stabilized against thermal degredation. While estersof aminocrotonic acid have been used to stabilize these resins, theyprovide very poor protection against early discoloration, such as thatocurring during mechanical processing and shaping.

We have discovered that the disadvantages of esters of aminocrotonicacid are overcome by the addition of small amounts of certainorganometal compounds. The organometal compounds exhibiting thisphenomenon are the alkyl and phenyl tin and lead oxides or sulfides.These compounds correspond to the formula:

wherein R, R and R" are alkyl radicals having 1 to 8 carbons or phenyl,Z is one-half oxygen or one-half sulfur, Me is tin or lead, a and b areor 1 and n is whole number.

Mono organometal compounds suitable for practicing the present inventioninclude stannoic acids and thiostannoic acids such as, methyl stannoicacid, butyl stannoic acid, hexyl stannoic acid, octyl stannoic acid,2-ethylhexyl stannoic acid, phenyl stannoic acid, methyl thiostannoicacid, butyl thiostannoic acid, hexyl thiostannoic acid, octylthiostannoic acid, 2-ethylhexyl thiostannoic acid and phenylthiostannoic acid. Diorgano and triorgano metal compounds suitable forpracticing the present invention are the oxides or sulfides of tin andlead. Examples include dimethyltin oxide, dimethyltin sulfide,trimethyltin oxide, trimethyltin sulfide, dibutyltin oxide, dibutyltinsulfide, tributyltin oxide, tributyltin sulfide, dioctyltin oxide,dioctyltin sulfide, trioctyltin oxide, trioctyltin sulfide, diphenyltinoxide, diphenyltin sulfide, triphenyltin oxide, triphenyltin sulfide,dimethyllead oxide, dimethyllead sulfide,dibutyllead oxide, dibutylleadsulfide, tributyllead oxide, tributyllead sulfide, diphenyllead oxide,diphenyllead sulfide, triphenyllead oxide and triphenyllead sulfide.

These organometalic compounds can be monomeric but are primarilyolemeric and polymeric. For examples, the acids may be polymeric and ifso correspond to the formulas (RSnO or (RSnS, The diorganometalcompounds can be simple oxides or sulfides or polymers of the formulasLielmlairl L M. L M.

The tris organometal compounds are bis oxides or sulfides correspondingto the formulas Although n maybe as great as 1000, 100 units is apreferred maximum.

Suitable esters for practicing the present invention are prepared byconventional methods from aminocrotonic acid and, mono,-diand trihydricaliphatic alcohols having 1 to 20 carbons and preferably 1 to 10 carbonssuch as methanol, ethanol, butanol, hexanol, octanol, decanol,dodecanol, stearol, isopropanol, sec. butanol, 2-ethyl hexanol, ethyleneglycol, propylene glycol, 1,4-butanediol, l,8-oc tanediol and2-ethyl-1-6-hexanediol. Alcohols containing ether and thioe'ther groupsare also suitable. Examples include 2-ethoxyethanol, 2-ethylthioethanol,0xydiethylene glycol, thiodiethylene glycol, oxydipropylene glycol,6-ethoxy hexanol and 4-ethyl mercapto octanol. Commercial mixtures ofaminocrotonic acid ester are also suitable.

The synergistic compositions of the present invention contain to 99.9weight per cent of the aminocrotonic acid ester and 0.1 to 10 weight percent of the organometal compound. Preferably, the compositions contain0.5 to 5 weight per cent of the organometal compound.

The synergistic compositions may be used as stabilizers in amounts of0.1 to 5 weight per cent of the resin and preferably in amounts of 1 to3 weight per cent.

Resins which are suitable for thermal stabilization with the synergisticcombinations of the present invention include polyvinyl chloride,polyvinylidene chloride, copolymers of vinyl chloride with vinylidenechloride, vinyl acetate and styrene as well as chlorinated mixtures ofpolyvinyl chloride and polyolefins.

EXAMPLES 2 g of a stabilizer were mixed into g of various polymers,milled for 5 minutes at 180C and sheeted off. The foils were thermallyexposed at C in a drying oven equipped with rotating supports. Atintervals of 15 minutes, samples were withdrawn and the discolorationobserved. The Tables contain the results for various combinations ofpolymers and stabilizers. Comparative samples were produced and tested,which contained the amino crotonic acid esters or organometal compoundsas the only stabilizer.

1n the Tables, the letters and Roman numerals identify the following:

A thiodiethylene glycol amino crotonate B mctylamino crotonateC=ethylene glycol amino crotonate D=oxydipropylene glycol aminocrotonate E=commercial amino crotonic acid ester mixture Fqnethylstannoic acid G=butyl stannoic acid H=butyl thiostannoic acid J=octylthiostannoic acid l=colorless K=phenyl stannoic acid ll=slight yellowingL=dibutyl tin oxide lll=yellow Mqiibutyl tin sulfide lV=orange N=dioctyltin oxide V=brown O=diphenyl tin oxide Vl=black P=diphenyl lead oxideQ=diphenyl lead sulfide Rqriphenyl tin oxide S=triphenyl lead oxideCommercial mixture of K- vulue from subsequently chlorinated IJOIyOltilHmid l Discoloration at 170 after minutes indicated.

Staliiliyvr IVti K-valuu x Commercial mixture of K- value 60 fromsubsequently chlorinated polyolelin and PVC 1 Discoloration at 170 afterminutes indicated.

What is claimed: 1. A heat stabilizer composition for halogen containingresins comprising an ester corresponding to the formula: NIH

wherein R is the residue of an alcohol having up to carbons selectedfrom the group consisting of an alkyl, alkoxyalkyl, alkylthioalkyl,hydroxyalkyl, hydroxyalkoxyalkyl, hydroxyalkylthioalkyl,

alkylthioalkyl and 0.1 to 10 weight percent based on said composition ofan organo metal compound corresponding to the formula [RR,,'R,,"MeZ:,wherein Me is tin or lead, R, R and R" are selected from the groupconsisting of alkyl having 1 to 8 carbons and phenyl when Me is tin, R,R and R" are phenyl when Me is lead, Z is oxygen or sulfur, a and b arezero or 1 and n is an integer of l to 1000.

2. The heat stabilizer composition of claim 1 wherein the organo metalcompound is present in an amount of 0.5 to 5 weight per cent correspondsto a formula selected from the group consisting of (RR'R"Sn) 0 and(RR'R"Sn) S wherein n is 2 to 100. 3. The heat stabilizer composition ofclaim 1 wherein the organo metal compound is present in an amount of 0.5to 5 weight per cent corresponds to a formula selected from the groupconsisting of ii Hill,

L M. L

(RRR"Pb) O and (RR'R"Pb) S wherein n is 2 to 4. The heat stabilizingcomposition of claim 1 wherein said ester is selected from the groupconsisting of thiodiethylene glycol amino crotonate, octylaminocrotonate, ethylene glycol amino crotonate and oxydipropylene glycolamino crotonate and said organo metal compound is present in an amountof 0.5 to 5 weight per cent and is selected from the group consisting ofmethyl stannoic acid, butyl stannoic acid, butyl thiostannoic acid,octyl thiostannoic acid, phenyl stannoic acid, dibutyl tin oxide,dibutyl tin sulfide, dioctyl tin oxide, diphenyl tin oxide, diphenyllead oxide, diphenyl lead sulfide, triphenyl tin oxide and triphenyllead sulfide.

5. A halogen containing resin composition comprising a resin selectedfrom the group consisting of polyvinyl chloride, polyvinylidenechloride, copolymers of vinyl chloride with vinylidene chloride, vinylacetate and styrene and mixtures of polyvinyl chloride and chlorinatedpolyolefins and 0.1 to 5 weight per cent of the stabilizer of claim 1.

6. A polyvinylchloride resin composition containing 1 to 3 weight percent of the stabilizer of claim 2.

7. A polyvinyl chloride resin composition of claim 6 wherein said resinis polyvinyl chloride containing 1 to 3 weight per cent of thestabilizer of claim 3.

2. The heat stabilizer composition of claim 1 wherein the organo metalcompound is present in an amount of 0.5 to 5 weight per cent correspondsto a formula selected from the group consisting of
 3. The heatstabilizer composition of claim 1 wherein the organo metal compound ispresent in an amount of 0.5 to 5 weight per cent corresponds to aformula selected from the group consisting of
 4. The heat stabilizingcomposition of claim 1 wherein said ester is selected from the groupconsisting of thiodiethylene glycol amino crotonate, octylaminocrotonate, ethylene glycol amino crotonate and oxydipropylene glycolamino crotonate and said organo metal compound is present in an amountof 0.5 to 5 weight per cent and is selected from the group consisting ofmethyl stannoic acid, butyl stannoic acid, butyl thiostannoic acid,octyl thiostannoic acid, phenyl stannoic acid, dibutyl tin oxide,dibutyl tin sulfide, dioctyl tin oxide, diphenyl tin oxide, diphenyllead oxide, diphenyl lead sulfide, triphenyl tin oxide and triphenyllead sulfide.
 5. A halogen containing resin composition comprising aresin selected from the group consisting of polyvinyl chloride,polyvinylidene chloride, copolymers of vinyl chloride with vinylidenechloride, vinyl acetate and styrene and mixtures of polyvinyl chlorideand chlorinated polyolefins and 0.1 to 5 weight per cent of thestabilizer of claim
 1. 6. A polyvinylchloride resin compositioncontaining 1 to 3 weight per cent of the stabilizer of claim
 2. 7. Apolyvinyl chloride resin composition of claim 6 wherein said resin ispolyvinyl chloride containing 1 to 3 weight per cent of the stabilizerof claim 3.